Percussion release hook



April 28, 1964 Filed Jan. 17, 1963 L. C. THOMPSON PERCUSSION RELEASE HOOK 2 Sheets-Sheet 1 INVENTOR. LAWRENCE c. THOMPSON IAII'ETOREEYE 7 A ril 28, 1964 L. C. THOMPSON PERCUSSION RELEASE HOOK 2 Sheets-Sheet 2 Filed Jan. 17, 1965 FIG. 4

, INVENTOR.

LAWRENCE C. THOMPSON 3,130,703 PERCUSSION RELEASE HOOK Lawrence C. Thompson, 9265 Fermi Ave., San Diego 23, Calif. Filed Jan. 17, 1963, Ser. No. 252,260 9 Claims. (Cl. 114-296) (Granted under Title 35, US. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

' This invention relates to coupling and release mech anisms and more particularly to a release mechanism actuated by an explosive charge housed in a structural member of the coupling. Specifically, the invention covers a hinged coupling in the form of a pelican type hook retained in a latched position by means of a hollow bolt containing an explosive charge and released by exploding the charge and fracturing said bolt.

In oceanographic exploration and detection work it is frequently necessary to submerge hydrophones, transducers and other scientific instruments to depths of several thousands of feet below the surface. This is accomplished by fastening a float to a bottom anchor by means of a support cable and suspending the scientific instrument on the cable at a predetermined depth or fixed distance from the bottom. This rig is connected by a hoisting cable extending to the ocean surface. The anchor, usually consisting of a heavy block of concrete to provide rapid vertical submergence, may be hoisted along with the scientific instruments after a fixed period of time for collecting data. However, the weight, water pressure and currents make it almost impossible for a surface ship maintaining steerageway, to recover the complete tackle. If the anchor weight could be made expendible and discarded under control of the surface ship, the efliciency of oceanographic surveys of this type would be greatly improved.

The general purpose of this invention is to overcome the disadvantages pointed out in the preceding paragraph and provide means for disengaging the test rig from the anchor at great depths underwater.

Another object is to provide a coupling and quick release device actuated by an explosive charge rupturing the bolt latching means and detonated by electrical means.

Another object is to provide an underwater cable coupling in the form of a pelican type hook retained in a closed position by a latching bolt containing an explosive charge adapted to be detonated and released by controlled electrical energy from the surface.

Another object is to provide a hinged coupling closed by a bolt containing an explosive charge and designed to be released by detonation of said charge so that the expansion of the explosive gases will physically force the hinge to open and drop the coupling load.

Another object is to provide a hinged coupling designed .so that the vertical line of force carried by the coupling is offset from the hinge pin whereby the force of gravity .will release the load when the coupling latch is released.

Another object is to provide a hinged coupling in the shape of apelican type hook and designed to replace the standard ring catch by a hollow bolt catch containing an explosive charge, and released by detonation whereby the force of the explosive gases in combination with the force of gravity open the hinge and drop the coupling load.

Another object is to provide an underwater coupling employing dual explosive actuated quick release devices interconnected by and supporting a single center load bar designed to be released if either or both devices function,

' thereby improving the efficiency'and reducing the per centage of miss-fires of the single type hook.

United, States Patent Another object is to provide a coupling and quick release device comprising a pair of pelican type hooks, each employing an exploisve bolt latching means as described above for the single hook but mounted on a frame and interconnected by a center load bar so that releaseof either or both hooks will in turn release said center load bar and its attached load.

Another object is to provide the bolt head chamber and stufiing box for assembling the explosive bolt and cable coupling, so that the explosive will be kept dry under extremely high hydrostatic pressures.

Other objects and advantages of the invention will become apparent from the following description and accompanying drawings in which like reference characters refer to like parts in several figures of the drawings in which:

FIG. 1 is an underwater elevational view of a cable supporting electronic devices and connected to an anchor by means of the subject coupling and percussion release hook.

FIG. 2 is a perspective view of the pelican type hook or coupling and percussion release means.

FIG. 3 is an enlarged side elevational view partially in section of the coupling and percussion release hook.

FIG. 4 is a perspective view of another species of the coupling employing a double pelican hook and interconnecting release bar.

The general use of the subject invention is shown in FIG. 1 in which an electronic instrument 44 is attached to a supporting cable 43 underwater and supported by a float 42 at a predetermined operational depth in the ocean above the bottom 41. The supporting cable 43 is detach ably connected by a coupling and release hook 45 to an anchor cable 47 and anchor 46. The release hook is a pelican type hook provided with an explosive bolt catch 13, FIG. 3, and is connected by detonating cable 14 to a buoy 48 at the ocean surface 40.

The base ship taking the desired readings merely drops the rig shown in FIG. 1 over the side whereby the heavy concrete block anchor 46 will quickly submerge the package to its proper depth for operation. At the end of the period for taking data the surface ship could hoist in the rig but due to the heavy anchor 46 combined with the pitch of the boat under steerageway, the chances of losing the tackle are serious. However, by employing the hook or release coupling 45, the expendible anchor will be 40 and will be recovered by the base ship.

The main invention resides in the coupling and release hook 45, a pelican type hook employing a hollow bolt 13 as a catch. Said bolt 13 is filled with an explosive charge 15 designed to release the coupling hook 17 by detonation under the control of the detonating cable 14 extending to the surface 40 where the base ship can fire the charge when desired. Timing means or remote control devices can also be used to automatically detonate the explosive charge 15 as required.

The coupling and release mechanism per se is shown in perspective in FIG. 2 and in cross-section in FIG. 3. The coupling consists of a shank section 18 and a pelican type beak or hook 17 hinged at its base or lower portion by pivot pin 23 to the shank hinge 22.

A slot or throat section 26 is provided in the beak 17 for detachably holding a pin 24 of shackle 25 which is automatically dropped when the beak 17 opens by rotating about pivot pin 23. By releasing the pin 24 and shackle 25, the anchor 46 and anchor cable 47 fastened to the shackle 25 throughrthimble 12, which are presumed to be expendible, are also released from the instrument rig attached to the float 42. The open or released hook 17 still remains hinged to the shank 18 which in turn remains fixed to the instrument rig orrsupporting cable 43 through thimble 11 and is recoverable.

The catch and releasing means is basically an explosive Patented Apr. 28, 1964 bolt 13 in place of the standard oval ring which encircles the shank and beak of a standard pelican hook. Matching keeper holes 19 and 21 are provided respectively in shank 18 and hook 17 through which the hollow bolt 13 as a catch can be inserted and secured by crimp nut 29.

The releasing feature results from detonating said bolt 13. The hollow bolt 13 is loaded with an explosive charge 15 subject to be detonated by caps or other suitable means connected to cable 14. In order to provide a design to assure the opening of the hook and effective release of the anchor load cable 47 upon firing of the bolt 13, a stop 37 has been provided on the shank surface adjacent the hook 17 so as to maintain the adjacent surfaces in slight spaced relationship and provide a limited clearance space of approximately one sixteenth of an inch wide as a defined release path for the explosive gases through which they may escape and open the gap between said surfaces.

7 At the same time the keeper holes 19 and 21 are provided with counter-sinks 20 at the adjacent surfaces of the shank 18 and hook 17. The clearance space provided by stop 37 and in addition the adjacent counter-sinks 20, leaves a small peripheral section 16 of the explosive bolt 13 not surrounded or encased by the keeper bores 19 and 21. The purpose for this design is to induce the bolt 13 to fracture along the unsupported peripheral break line 16.

In operation, when the bolt 13 explodes and splits along said break line 16, its walls are swaged into the countersinks 20 thus fixing the separated bolt sections as integral parts of keepers 19, and 20.

This deformation provides a firm structural backing to force the gases from the bolt explosion out through the only escape clearance space as provided by stop 37 between the shank 18 and hook 17 The gas pressure operates against the separated bolt sections swaged in position plus the opposed areas of the clearance space between the shank and hook, and the resultant force tends to open the hook 17 and release the anchor load.

Another feature of the coupling design resides in the vertical line or direction of force between the supporting cable 43 and anchor cable 47 through the load shackle pin 24. In FIG. 3 this line 49 is shown to the right of the axis of binge pin 23 and therefore it sets up a vector of gravitational force tending also to open the hook and release the anchor load as an assist to the explosive gas pressure forces described above.

An additional feature of the device is the bolt head protection chamber 27 which serves two purposes. First the chamber 27 is water tight and protects the openings in the bolt 13 through which the wires from the detonating cable 14 pass to the explosive charge 15, so that water will not be forced into the hollow bolt 13 as a result of the extremely high hydrostatic pressure. The stuffing tube 32 provides the detonating cable entrance for the chamber 27. A second feature of the chamber is to provide means for assembling the explosive catch bolt 13 in its armed position as shown in FIG. 3. A screw cap 30 sealed by ring 31 provides the entrance in chamber 27 for assembling the bolt 13 and arming it for detonation.

In the pelican type hook described above, should it fail to detonate or the hook to open, the entire operation is lost. In FIG. 4 a dual coupling is shown wherein if either charge 15 detonates or either hook opens, the releasing operation will be completed. Therefore, the species of coupling shown in FIG. 4 is more efiicient in that it greatly reduces the number of possible failures to an insignificant amount, since both hooks must fail at the same time to cause malfunction.

The dual coupling FIG. 4 comprises a pair of pelican type hooks as described above as a single unit, but crossbraced by upper and lower tandem bars 33 and 34 respectively. The tandam bar 33 is attached to the shanks 18 by short bolts through the standard support thimble opening. Studs 35 are provided for fastening tandem bar 34 to the shanks 18 thus making the shanks integral members of said frame, In place of the shackle pin 24 FIG. 3, a center load bar 36 spans the gap between the hooks 17. The load bar 36 is of a general U shape terminating in formed pivotal ends. Said pivotal ends are in axial alignment and detachably supported in the throats 26 of the respective beak sections or hooks 1'7. This structure operates to release the bar 36 as the hooks 17 swing away from their shanks 18. However, if either hook 17 releases, even though the other hook fails, its respective load bar end will be released and in turn the other end will slip out of the throat 26 due to the ample clearance provided, thus dropping the bar 36 and its load.

Still another detail of the dual hook structure includes its line of supporting force similar to line 49 of the single hook in FIG. 3. The supporting cable thimble 51, FIG. 4, and the anchor cable center load bar 36, when under load as in FIG. 1, would be oif-set from hinge pins 24 so as to tend to open the hooks 17 by gravity alone when released by detonation of bolts 13. The above follows when bar 33 is on the opposite side of the shanks 18 from the hooks 1'7.

What is claimed is:

l. A pelican type coupling hook employing an explosive bolt'catch and release mechanism comprising,

(a) a hook shank suspended from a supporting cable,

(b) a hook hinged to said shank by apivot pin,

. (c) a slot in said hook between the bolt catch and pivot (d) an anchor cable detachably supported by a shackle pin in said slot,

(c) said supporting cable, anchor cable, and shackle pin being in vertical alignment when under load;

(f) said line of vertical alignment being outside the axis of said hinge pivot pin so that upon release the force of gravity on said shackle pin will tend to swing the hook on said hinge pivot pin away from the shank and release the shackle pin,

(g) a bolt catch is located in aligned keeper holes through said shank and hook respectively for securing said hinged hook to said shank in a closed position,

(11) said catch bolt being hollow and filled with an explosive charge,

(i) detonating means connected through said bolt head to said explosive charge,

(1') a bolt head chamber for protecting the armed bolt from hydrostatic pressure,

(k) a sealed horizontal opening in said chamber for assembling said catch bolt in its armed position,

(I) a stuffing box connected to said chamber for providing a watertight detonating cable connection to said chamber;

(In) the adjacent surfaces of said shank and hook surrounding said bolt being separated approximately of an inch apart for forming an unsupported peripheral break line and a spacing so that the escaping explosive gases through said space will tend to force said shank and hook apart;

(n) said keeper bolt holes being counter-sunk so that, as said bolt ruptures along said break line between shank and hook, it will be swaged into said countersinks to provide a firm backing for said explosive gases.

2. A pelican type coupling hook employing an explosive bolt catch and release mechanism, comprising;

(a) a hook shank suspended from a supporting cable;

(11) a hook hinged to said shank by a pivot pin;

(0) a slot in said hook between the bolt catch and pivot pin;

(d) an anchor cabledetachably supported by a shackle pin in said slot;

(e) said supporting cable, anchor cable, and shackle pin being in vertical alignment when under load;

(f) said line of vertical alignment being outside the axis of said hinge pivot pin so that upon release the force of gravity on said shackle pin will tend to swing the hook on said hinge pivot pin away from the shank and release the shackle pin;

(g) a bolt catch located in aligned keeper holes through said shank and hook respectively for securing said hinged hook to said shank in a closed position;

(It) said catch bolt being hollow and filled with an explosive charge;

(i detonating means connected through said bolt head to said explosive charge;

(j) means for protecting the bolt head and detonating cable from hydrostatic pressure fluid;

(k) the adjacent surfaces of said shank and hook surrounding said bolt being separated approximately of an inch apart forming an unsupported peripheral break line and a spacing so that the escaping explosive gases through said space will tend to force said shank and hook apart;

(I) said keeper bolt holes being counter-sunk so that, as said bolt ruptures along said break line of division between shank and hook, it will be swaged into said counter-sink to provide a firm backing for said explosive gases.

3. A pelican type coupling hook employing an explosive bolt catch and release mechanism;

7 (a) a hook shank suspended from a supporting cable;

(b) a hook hinged to said shank by a pivot pin;

(0) a slot in said hook between the bolt catch and pivot pin;

(d) an anchor cable detachably supported by a shackle pin in said slot;

(e) said supporting cable, anchor cable, and shackle pin being in vertical alignment when under load; (1) said line of vertical alignment being outside the axis of said pivot pin so that upon release the force of gravity on said shackle pin will tend to swing the hook on said hinge pivot pin away from the shank and release the shackle pin;

(g) a bolt catch located in aligned keeper holes through said shank and hook respectively for securing said hinged hook to said shank in a closed position;

(h) said catch bolt being hollow and filled with an explosive charge;

(1') detonating means connected through said bolt head to said explosive charge;

(j) means for protecting the bolt head and detonating means from hydrostatic pressure fluid;

(k) adjacent surfaces of said shank and hook being maintained in close proximity and the bolt holes counter-sunk to form a swage block for the exploded catch bolt so that the adjacent surfaces will firmly resist the gas pressure of the explosion and force the hook to open.

4. A pelican type coupling hook employing an explosive bolt catch and release mechanism, comprising;

(a) a hook shank suspended from a supporting cable,

(b) a hook hinged to said shank by a pivot pin,

(a) a slot in said hook between the bolt catch and pivot pin,

(d) an anchor cable detachably supported by a shackle pin in said slot,

(e) said supporting cable, anchor cable, and shackle pin being in vertical alignment when under load,

(1) said line of vertical alignment being outside the axis of said hinge pivot pin so that upon release the force of gravity on said shackle pin will tend to swing the hook on said hinge pivot pin away from the shank and release the shackle pin,

(g) an explosive keeper bolt for securing said hinged hook to said shank,

(h) detonating means for exploding said bolt and releasing said hook,

(i) adjacent surfaces of said shank and hook being maintained in close proximity and the bolt holes counter-sunk to form a swage block for the exploded 6 catch bolt so that the adjacent surfaces will firmly resist the gas pressure of the explosion and force the hook to open.

5. A coupling and release mechanism comprising: (a) a pair of pelican type coupling hooks hinged side by side on a common axis to supporting frames, (b) said frame being suspended from a supporting cable,

(0) each hook being provided with an explosive bolt catch and release mechanism,

(d) means for detonating said exposive bolts,

(e) a U-shaped center load bar connected to an anchor cable,

(1) said U bar having its outwardly-extending flange portions pivoted in and detachably supported on a common axis by respective hooks so that the detonation of either or both explosive bolts will release said bar and its anchor cable,

(g) said supporting cable, anchor cable, and the pivot point of the center load bar being in vertical alignment when under load;

(h) said line of vertical alignment being outside the horizontal axis of the pins hinging said pair of hooks to the supporting frame so that the force of gravity on said center load bar will tend to swing the hooks away from the supporting frame and release the center load bar and anchor cable.

6. An underwater cable coupling and release mechanism comprising:

(a) a plurality of pelican type coupling and release hooks mounted side by side on a supporting frame,

(b) said frame being suspended from a supporting cable,

(0) each hook including a shank portion forming an integral member of said frame and a beak section hinged at its base to the lower end of its respective shank,

(d) a center load bar connected to an anchor cable,

(e) said load bar having its ends pivoted in and detachably supported by said respective hooks so that the explosion of either or both bolts will release said bar and its anchor cable,

(f) said supporting cable, anchor cable, and the pivot point of the center load bar being in vertical alignment when under load,

(g) said line of vertical alignment being outside the horizontal axis of the pins hinging said beak sections to said shanks so that force of gravity on said center load bar will tend to swing the beak sections away from the shank portions of the supporting frame and release the center load bar and anchor cable,

(h) a keeper opening through the upper free end of each hinged beak section and its respective shank, (i) a hollow bolt catch extending through each keeper opening for detachably fastening the beak and shank in closed position,

(j) an explosive charge located in each hollow bolt,

(k) detonating means connected to said charges for exploding said bolts and releasing said beaks,

(1) bolt head chambers for protecting the armed bolts against leaks resulting from hydrostatic pressure, (m) a sealed horizontal opening in each chamber for assembling said bolt in its armed position,

(n) the adjacent surfaces of the respective shank and beak sections being slightly separated by a stop so that escaping gases from the explosion will be pressure pocketed between said adjacent surfaces and tend to force them apart,

(0) the keeper openings at the adjacent surfaces of the hinged beak section and said shank being countersunk so that as said bolts rupture along the break line the bolts will be swaged into said counter sinks and provide a firm pressure backing for said explosive gases.

7. A coupling and release mechanism comprising:

(a) a pelican type hook including a shank and a beak portion hinged to said shank,

(b) a hollow bolt catch connecting the shank and beak portion for keeping said hook closed,

(c) an explosive charge located in said hollow bolt for exploding said bolt and releasing said hook,

(d) means for detonating said charge,

(e) a cable suspending said shank,

(f) a slot provided in said beak portion between the hinge pin and bolt catch,

(g) an anchor cable detachably supported by a shackle pin in said slot,

(h) said supporting cable, anchor cable and shackle pin being in vertical alignment when under tension, and

(i) said line of vertical alignment being outside the axis of said hinge pin so that upon release the force of gravity on said shackle pin will tend to swing the hook on said hinge pin away from the shank and release the shackle pin,

(j) the adjacent surfaces of the shank and beak portion of the hook being approximately parallel and maintained in slight spaced relationship by a stop so that an unsupported break line is provided for the exploding bolt and a defined release path for the explosive gases.

8. A coupling and release mechanism comprising:

(a) a pelican type hook including a shank and a beak portion hinged to said shank,

(b) a hollow bolt catch connecting the ,shank and beak portion for keeping said hook closed;

() an explosive charge located in said hollow bolt for exploding said bolt and releasing said hook,

(d) means for detonating said charge,

(e) aligned keeper holes being provided in the shank and beak portions for receiving said hollow bolt catch, and

(1) said keeper holes being counter-sunk at the adjacent surfaces of the shank and beak so that the sections of the exploding bolt catch will be swaged into said countersinks and form firm structural backing for the exploding gases.

9. A pelican-type coupling hook comprising:

(a) a suspension line,

(b) a fiat-sided elongate bar-shaped shank portion suspendably supported at one end in a vertical disposition by said line and formed at its other end with a hinge flange extending laterally-outwardly from one side of said shank,

(c) a protective box-like chamber carried on the opposite side of said shank,

(d) a bar-shaped hook portion pivotally-coupled at its lower end on a horizontal axis to said flange,

(2) said shank being provided medially and said hook being provided at its upper end with aligned keeper holes,

(f) a keeper bolt mounted in said holes for securing said hook to said shank,

(g) said bolt being hollow for encasing an explosive charge,

(It) said bolt having an end portion projecting into said chamber,

(i) charge-firing means coupled to said charge through said chamber and bolt end,

(i) said hook being formed medially of its keeper hole and pivot axis with a slot, and

(k) a weight-supporting shackle pin means releasably carried in said slot,

(1) whereby a discharge of said explosive ruptures said bolt for releasing said hook whereupon said hook swings downwardly for releasing, said shackle and weight,

(m) said suspension line, weight and shackle pin being in vertical alignment when under tension and said line of vertical alignment being outside of said pivot axis.

References Cited in the file of this patent UNITED STATES PATENTS 1,531,550 Glennon Mar. 31, 1925 2,981,074 Wilder Apr. 25, 1961 3,012,810 Tenney Dec. 12, 1961 

1. A PELICAN TYPE COUPLING HOOK EMPLOYING AN EXPLOSIVE BOLT CATCH AND RELEASE MECHANISM COMPRISING, (A) A HOOK SHANK SUSPENDED FROM A SUPPORTING CABLE, (B) A HOOK HINGED TO SAID SHANK BY A PIVOT PIN, (C) A SLOT IN SAID HOOK BETWEEN THE BOLT CATCH AND PIVOT PIN, (D) AN ANCHOR CABLE DETACHABLY SUPPORTED BY A SHACKLE PIN IN SAID SLOT, (E) SAID SUPPORTING CABLE, ANCHOR CABLE, AND SHACKLE PIN BEING IN VERTICAL ALIGNMENT WHEN UNDER LOAD; (F) SAID LINE OF VERTICAL ALIGNMENT BEING OUTSIDE THE AXIS OF SAID HINGE PIVOT PIN SO THAT UPON RELEASE THE FORCE OF GRAVITY ON SAID SHACKLE PIN WILL TEND TO SWING THE HOOK ON SAID HINGE PIVOT PIN AWAY FROM THE SHANK AND RELEASE THE SHACKLE PIN, (G) A BOLT CATCH IS LOCATED IN ALIGNED KEEPER HOLES THROUGH SAID SHANK AND HOOK RESPECTIVELY FOR SECURING SAID HINGED HOOK TO SAID SHANK IN A CLOSED POSITION, (H) SAID CATCH BOLT BEING HOLLOW AND FILLED WITH AN EXPLOSIVE CHARGE, (I) DETONATING MEANS CONNECTED THROUGH SAID BOLT HEAD TO SAID EXPLOSIVE CHARGE, (J) A BOLT HEAD CHAMBER FOR PROTECTING THE ARMED BOLT FROM HYDROSTATIC PRESSURE, (K) A SEALED HORIZONTAL OPENING IN SAID CHAMBER FOR ASSEMBLING SAID CATCH BOLT IN ITS ARMED POSITION, (L) A STUFFING BOX CONNECTED TO SAID CHAMBER FOR PROVIDING A WATERTIGHT DETONATING CABLE CONNECTION TO SAID CHAMBER; (M) THE ADJACENT SURFACES OF SAID SHANK AND HOOK SURROUNDING SAID BOLT BEING SEPARATED APPROXIMATELY 1/16 OF AN INCH APART FOR FORMING AN UNSUPPORTED PERIPHERAL BREAK LINE AND A SPACING SO THAT THE ESCAPING EXPLOSIVE GASES THROUGH SAID SPACE WILL TEND TO FORCE SAID SHANK AND HOOK APART; (N) SAID KEEPER BOLT HOLES BEING COUNTER-SUNK SO THAT, AS SAID BOLT RUPTURES ALONG SAID BREAK LINE BETWEEN SHANK AND HOOK, IT WILL BE SWAGED INTO SAID COUNTERSINKS TO PROVIDE A FIRM BACKING FOR SAID EXPLOSIVE GASES. 